RU2705131C1 - Method for gasification of solid fuel using mechanical and plasma action and device for its implementation - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to power engineering and can be used in solid fuel combustion. Device for gasification of solid fuel using mechanical and plasma action includes fuel crushing unit, vortex channel, nozzle for fuel supply and plasmatrons, interconnected units of the first and the second gasification stages, made with provision of serial flow of fuel and plasma flow from the unit of the first stage to the unit of the second stage. Fuel crushing unit is made in form of hydraulic percussion unit of wet grinding and comprises closed volume with moving and fixed impact surfaces, channels for solid fuel loading and water supply to closed volume, and also pump for fuel supply in the form of water emulsion from crushing unit to unit of the first stage of gasification, plasmatrons of gasification units are steam plasmotrons with a conical interelectrode chamber and are made with supply of synthesis gas CH₄ and steam with possibility of adjusting temperature and flow rate of plasma, unit of first stage of gasification is made in form of vortex channel, in which a fuel supply nozzle in the form of an aqueous emulsion is installed, which is arranged to provide fuel supply along a tangent to the vortex channel cross section from top to bottom, and in the zone of the opposite quadrant of the circle circumference of the vortex channel there is a plasmatron provided with supply of the plasma jet at a tangent to the vortex channel cross section from below upwards, second plasmatron is located at end of vortex channel to feed plasma jet along vortex channel, unit of second stage of gasification is located below unit of first stage of gasification and equipped with two plasmatrons.

EFFECT: technical result of invention is to ensure homogeneity of propellant mixture before feeding into gasification chamber without the need for its mechanical activation, avoiding the need to separate fine and coarse fractions, eliminating reaction products in the form of oxides.

3 cl, 2 dwg

Description

The invention relates to the field of energy and can be used for gasification of solid fuels.

A known analogue is a method of burning coal dust in a swirl furnace - RU 25983628, 01/19/2009, including grinding, mechanical activation and combustion, characterized in that part of the coal after grinding is sent to the disintegrator chamber, and then to the flame backlight burner, while the main part of the coal after grinding is directly introduced by injection into the combustion chamber of the vortex furnace, while the flame of the backlight burner is sent directly to the area between two air flows rotating in opposite directions relative to each other.

The disadvantage of the analogue is low energy efficiency, due to the large energy costs for mechanical activation, as well as low environmental friendliness due to the likelihood of oxidative reactions with the release of carbon and nitrogen oxides.

A known analogue is a method of burning coal subjected to mechanical and plasma processing - RU 2631959, 08/23/2016, adopted as a prototype of the method, including mechanical activation, ignition and combustion, characterized in that the coal is preliminarily crushed and divided into fine and coarse fractions, from which finely divided coal fraction is subjected to mechanical activation and fine-tuning the fineness to a particle size of 40 microns or less, then the obtained micron grind coal is introduced tangentially by injection into the first gasification stage and ignite using the starting plasma torch, and the input is carried out in the direction opposite to the tangential injection of the plasma jet from the starting plasma torch, the coarse coal fraction, the air flow and coal combustion products from the first gasification stage are simultaneously introduced into the second gasification stage tangentially to it the longitudinal axis and in one plane perpendicular to the longitudinal axis of the second gasification stage, the pulverized coal mixture is ignited using of coal combustion micro-grinding using the heat of combustion of coal micro-grinding, while the efficiency of the gasification and combustion of the pulverized-coal mixture in the second gasification stage is ensured by the pulsed inclusion of the additional control plasma torch, and the plasma jet is injected from the additional control plasma torch along the axis of the second gasification stage, perpendicular to the plane entering the pulverized coal mixture and in the direction coinciding with the direction of axial movement of the products of combustion Ia pulverized coal mixture within the second gasifying stage.

A known analogue is a device for burning coal using mechanical and plasma processing - RU 2631959, 08/23/2016, adopted as a prototype of a device containing a fuel crushing unit, a vortex channel, nozzles for supplying fuel and plasmatrons, interconnected units of the first and second stages of gasification made to ensure sequential passage of the flow of fuel and plasma from the block of the first stage to the block of the second stage

The disadvantage of prototypes is low manufacturability due to the need for separation into finely divided and coarse fractions, low energy efficiency due to increased energy consumption for mechanical activation, low environmental friendliness due to the presence of nitrogen and carbon oxides as process products, due to the presence of an air mixture during gasification reactions .

An object of the invention is to improve the manufacturability, energy efficiency and environmental friendliness of the process of degassing solid fuels.

The technical result of the invention is to ensure uniformity of the fuel mixture before feeding into the gasification chamber with less energy, providing gasification with less energy, providing a gasification process without the reaction products of the process in the form of nitrogen and carbon oxides and impurities that are environmentally harmful.

The technical result is achieved by the fact that the method of gasification of solid fuel using mechanical and plasma effects includes the mechanical preparation of solid fuel containing a crushing operation, and two stages of gasification, gasification includes the input of the flow of prepared fuel across the vortex channel towards the plasma jet, injection of the plasma jet from an additional control plasmatron along the axis of the vortex channel, mechanical preparation is carried out by repeatedly colliding pieces of fuel about b the impact surfaces of the grinding equipment and water with the formation of an aqueous emulsion, fuel in the form of an aqueous emulsion is supplied from the nozzle from the nozzle from top to bottom of the vortex channel tangentially to the vortex channel at the first gasification stage, and tangentially from the opposite quadrant of the vortex channel cross section circumference to the circumference of its cross section is fed upwards from below the plasma jet formed by passing through the plasma torch and ionized synthesis gas of CH _4, thereby providing images Contents of the standing wave vortex tornado plasma jet of the auxiliary torch to form the synthesis gas mixture of CH ₄ with water vapor in the ratio required for the gasification reactions to release the synthesis gas of CH ₄ and water, is carried out final gasification of the fuel in the second stage with the use of plasma torches as a source of energy.

The technical result is achieved by the fact that the device for implementing the method of gasification of solid fuel using mechanical and plasma effects contains a block of crushing fuel, a vortex channel, a nozzle for supplying fuel and plasmatrons, interconnected blocks of the first and second stages of gasification, made to ensure consistent flow fuel and plasma from the first stage block to the second stage block, the fuel crushing block is made in the form of a wet grinding wet blast block and contains a curved volume with moving and stationary shock surfaces, channels for loading solid fuel and supplying water to a closed volume, as well as a pump for supplying fuel in the form of an aqueous emulsion from the crushing unit to the unit of the first gasification stage, the plasma torches of the gasification units are steam plasmatrons with a conical transconductance chamber and operable to supply synthesis gas _CH4 and steam, with the temperature control and plasma flow, the block first gasification stage is designed as a vortex channel in a the torus has a fuel supply nozzle in the form of an aqueous emulsion, which is arranged to supply fuel in a tangent to the circumference of the vortex channel cross section from top to bottom, and in the area of the opposite quadrant of the vortex channel cross section circumference, a plasma torch is installed to ensure the plasma jet is tangential to the circumference of the vortex channel cross section channel from the bottom up, from the end of the vortex channel there is a second plasmatron with the possibility of supplying a plasma jet along the vortex channel, the block of the second tim gasification unit is located below the first gasification stage and provided with two plasma torches. A turbine driven by a high-speed electric motor with magnetic bearings can be used to supply CH ₄ synthesis gas to the plasma torches.

In FIG. 1 shows a diagram of a device for implementing the method of gasification of solid fuel using mechanical and plasma effects.

In FIG. 2 shows a cross section of a vortex channel.

A device for implementing the method of gasification of solid fuel using mechanical and plasma effects, a diagram of which is shown in FIG. 1, contains a fuel crushing unit 1, a vortex channel 2, a nozzle 3 for supplying fuel, and plasmatrons 4, 14, 15, interconnected blocks of the first 5 and second 6 gasification stages, made to ensure consistent passage of the fuel and plasma flow from the first stage block 5 to the second stage unit 6, the fuel crushing unit 1 contains a closed volume with moving 7 and fixed 8 impact surfaces, channels for loading solid fuel 9 and supplying water 10 to the closed volume, and also a pump 11 for supplying fuel in the form of an aqueous emulsion from crushing 1 into block 5 of the first gasification stage, plasmatrons 4 of gasification blocks 5, 6 are steam plasmatrons with a conical interelectrode chamber and are configured to be powered by CH ₄ synthesis gas and steam with the possibility of adjusting the temperature and plasma flow, block 5 of the first stage gasification is made in the form of a vortex channel 2, in which a fuel supply nozzle 3 is installed in the form of an aqueous emulsion, which is arranged to provide fuel supply tangentially to the circumference 12 of the cross section of the vortex channel 2 from above bottom (FIG. 2), and in the zone of the opposite quadrant 13 of the circumference 12 of the cross section of the vortex channel 2, a plasmatron 4 is installed to provide a plasma jet tangentially to the circumference of the cross section of the vortex channel from the bottom up, from the end of the vortex channel 2 there is a second plasma torch 14 with the possibility of supplying a plasma jet along vortex channel 2, the block of the second stage of gasification 6 is located below the block of the first stage of gasification 5 and is equipped with two plasmatrons 15.

Consider an example of a specific implementation of a device for implementing the method of gasification of solid fuel using mechanical and plasma effects. The device in the example of a specific implementation is intended for gasification of coal and generation of electric energy by burning CH ₄ synthesis gas in a gas generator. The fuel crushing unit 1 consists of a coal hopper, a coal dispenser, a grinding unit, a metal separator, a pump 11, as well as a control cabinet. The crushing unit capacity is up to 5 tons of coal per hour. As plasma torches 4, 14, 15 electric arc plasma torches of a direct current EDP-145 are used. A turbine with a high-speed electric motor with magnetic bearings with a rotation speed of up to 20,000 rpm is used to supply the CH ₄ synthesis gas to the plasmatrons 4, 14, 15. Magnetic bearings reduce energy loss while maintaining the high speeds needed to ensure high gas flow rates. All processes of loading, activation of plasmatrons, plasma confinement, plasma control using a gas analyzer, plasma velocity, formation and quality of gas synthesis, cooling, are automated using Advent industrial computer. The body of the gasification device is made on the principle of a high-vacuum-high-temperature chamber, all flanges are made with cooling channels, the body has a cooling jacket. Connecting seals are made of vacuum rubber, which does not allow even the smell of burning. At the end of the vortex channel 2, there is a second plasmatron 14 with the possibility of supplying a plasma jet along the vortex channel 2. With this plasmatron, if necessary, you can add the necessary reagents, water or synthesis gas, and increase the temperature to the required values. The plasma flow of this plasmatron presses on the plasma donut formed by a vortex tornado received by the ionized gas of the plasmatron 4 and fuel from the nozzle 3, drawing a plasma jet along the vortex channel 2 into the second gasification stage 6. In the second gasification stage 6, a capsule block is provided, into which, if necessary sand SiO ₂ can be supplied and fused with carbon, thus obtaining an inert safe product - Obsidian. The second stage of gasification 6 is necessary for gasification of unreacted fuel due to the possible supply of substandard fuel, or an increased content of the water component.

Consider an example of the implementation of the method of gasification of solid fuel using mechanical and plasma effects. Hard coal is loaded into the crushing unit 1. Water is supplied to the crushing unit 1. To crush coal by impacting its particles on the impact surfaces of grinding equipment, which is a crushing unit, 5 times less energy is spent than in plants where coal is crushed by compression and then mechanically activated to introduce a uniform homogeneous fuel flow into the gasification chamber. An incompressible liquid, the water involved in the crushing process, transfers the energy of the shock elements to the milled coal particles, which also reduces the energy costs of grinding. The use of a wet blasting block of wet grinding provides very fine grinding up to 10-20 microns with simultaneous activation in one medium - coal is combined with water to form a very fluid plastic homogeneous mixture. Due to this, gasification processes proceed uniformly without voltage and pressure surges, which increases the processability. In addition, the technology of wet crushing dedusts the room, thereby increasing manufacturability, eliminating the need for special measures to protect equipment and other rooms from dust. Water in the composition of the emulsion directed to gasification is a source of hydrogen, which during the gasification reaction provides synthesis gas CH ₄ . And also water ensures the homogeneity of the mixture supplied to gasification, eliminating the need for energy consumption for additional mechanical activation, which is present in the analogous methods. To ensure the gasification of such fuel, steam plasmatrons are used, which ensure operation in the presence of water vapor, and also add water to the ionized mixture in addition to the synthesis of CH ₄ gas. This eliminates the need to add oxygen or air to ensure gasification reactions, which ensures high environmental friendliness of the process, since among the reaction products in this case there are no environmentally harmful carbon and nitrogen oxides. Due to the flow into the vortex channel 2 tangentially to the circumference 12 of the vortex channel cross-section from the nozzle 3 of the fuel in the form of an aqueous emulsion, and from the zone of the opposite quadrant of the circumference of the vortex channel cross section tangentially to the circle 12 of its cross section from the bottom up, the plasma jet is formed a standing wave of a whirlwind tornado, which is characterized by high voltage and temperature in the plasma vent up to 35000 ° С. Due to this, gasification reactions C + H ₂ O = CO + H ₂ , CO + 3H ₂ = CH ₄ + H ₂ O are accelerated. This leads to an increase in the productivity of the device without a significant increase in the contribution of external energy, thereby increasing the energy efficiency of the process. The acceleration of reactions and the high temperature eliminates the occurrence of undesirable intermediate reactions with the formation of unnecessary harmful products and impurities, thereby increasing the environmental friendliness of the process. In the presence of intermediate reactions, the products of which would not have time to react, the appearance of soot, contamination of equipment. Due to the increased temperature and pressure in the whirlwind, this is eliminated, increasing the manufacturability of the process - there is no need to clean the equipment and provide for additional measures. In this case, all substances dissociate without waste, per 1000 kg of substance up to 1 kg of waste - structural carbon - white ash. The plasma jet of the auxiliary plasmatron is formed by a mixture of CH ₄ synthesis gas with water vapor in the ratio necessary for gasification reactions to produce CH ₄ synthesis gas and water, which provide simple control over the efficiency of the process, thereby increasing its manufacturability.

Claims (3)

1. The method of gasification of solid fuel using mechanical and plasma effects, including the mechanical preparation of solid fuel, containing the operation of crushing, and two stages of gasification, gasification includes the introduction of the flow of prepared fuel across the vortex channel towards the plasma jet, injection of the plasma jet from an additional control plasma torch along the axis vortex channel, characterized in that the mechanical preparation is carried out by repeatedly impacting pieces of fuel on shock surfaces on the first stage of gasification, fuel is supplied in the form of an aqueous emulsion from the nozzle from top to bottom from the nozzle of the opposite quadrant of the circumference of the cross section of the vortex channel tangential to the circle its cross section is fed upwards from below the plasma jet formed by passing through the plasma torch and ionized synthesis gas of CH _4, thereby provide for the formation of a standing wave s whirling a tornado, the plasma jet of the auxiliary torch to form the synthesis gas mixture of CH ₄ with water vapor in the ratio required for the gasification reactions to release the synthesis gas of CH ₄ and water, is carried out final gasification of the fuel in the second stage with the use of plasma torches as a source of energy. 2. A device for implementing a method of gasification of solid fuel using mechanical and plasma effects, containing a block of crushing fuel, a vortex channel, a nozzle for supplying fuel and plasmatrons, interconnected blocks of the first and second stages of gasification, made to ensure consistent passage of the flow of fuel and plasma from a block of the first stage to a block of the second stage, characterized in that the block of crushing fuel is made in the form of a hydraulic hammer block of wet grinding and contains a closed volume with two burning and fixed shock surfaces, channels for loading solid fuel and supplying water to a closed volume, as well as a pump for supplying fuel in the form of an aqueous emulsion from the crushing unit to the first stage of gasification, the plasma torches of the gasification units are steam plasmatrons with a conical interelectrode chamber and made with the supply of synthesis gas CH ₄ and steam with the possibility of adjusting the temperature and plasma flow, the block of the first stage of gasification is made in the form of a vortex channel in which is installed and a fuel supply nozzle in the form of an aqueous emulsion, arranged to supply fuel tangentially to the circumference of the vortex channel cross section from top to bottom, and in the area of the opposite quadrant of the vortex channel cross section circumference, a plasma torch is installed to ensure the plasma jet is tangential to the circumference of the vortex channel cross section from the bottom up, from the end of the vortex channel there is a second plasmatron with the possibility of supplying a plasma jet along the vortex channel, the block of the second gasification stage Position the lower unit of the first gasification stage and provided with two plasma torches. 3. A device for implementing the method of gasification of solid fuel using mechanical and plasma effects according to claim 2, characterized in that there is a turbine driven by a high-speed electric motor with magnetic bearings for supplying CH ₄ synthesis gas to the plasma torches.

Images